Firewall software

I have been happily using the free firewall software from zonealarm, which I like because it doesn’t have a lot of pop ups – i find those things annoying. My friend said I should upgrade to the firewall pro – but I don’t know if it’s worth the money. The pro version from zonealarm is only $30 and it comes with antispywear and identity theft protection – but I’m still not sure why upgrading is necessary. Can someone please tell me if any of the features on the pro software are worth the upgrade:
http://www.zonealarm.com/security/en-us/zonealarm-pro-firewall-anti-spyware.htm